Modern irrigation systems such as lawn sprinklers usually include multiple watering or sprinkling zones. The user typically sets a timer to instruct the sprinkler system to water a lawn at pre-programmed times. When the timer reaches a pre-programmed time, the system cycles through watering the various sprinkling zones. In this manner, each zone receives that water that it needs.
Unfortunately, simple sprinkler systems often waste water because the programmed sprinkling time occurs immediately before, during or after a natural rainstorm event. When such a natural rainstorm event occurs, there is no need for irrigation. Unwarranted sprinkling at these times may cause significant water waste. Some modern irrigation systems address this problem by employing a rain gauge to act as a sensor that prevents the sprinkler system from activating if it collects water prior to the programmed sprinkling time. One significant drawback of this approach is that it ignores rain that occurs soon after the programmed sprinkling time. For example, it is possible that a sprinkler system employing a rain gauge sensor may water the lawn as scheduled time at 6 am when there is no water in the rain gauge. However, if a rainstorm occurs the same day at 2 pm, then the 6 am watering event represents wasted water.
What is needed is an irrigation method and apparatus that addresses the above irrigation water waste problem.